Considerable work has been done on optimization and mechanization of the combinational and sequential logic design, but so far, none of the current methods have found a broad industrial application. Therefore, it is the purpose of this invention to provide a means broadly applicable for automation and optimization of the logic design process.
To lower the cost of logic controllers, some Large Scale Integrated(LSI) circuits, such as Programmable Logic Arrays, have been developed. Most of these chips, however, do not provide for sequential logic circuits. Therefore, it is another purpose of this invention to provide for a versatile type of chip, capable of providing combinational and sequential logic circuits.
The aforementioned Programmable Logic Arrays do not use the chip area as efficiently as Read Only Memories (ROM). Therefore, it is still another purpose of this invention to provide the logic circuits on highly efficient ROM chip structures.
The standard microprocessors have a plurality of instructions, to allow for a broad scope of applications. This, however, makes the instruction word and consequently the size of the required ROM less than optimal for any one particular application. Therefore, it is yet another purpose of this invention to provide for optimal usage of ROM memory in logic applications by providing an optimal logic operations instruction set.
Standard microprocessors process all input data serially, which results in a slow processing speed. To speed up the operation, a parallel fed microprocessor could be added, but at a considerable increase in hardware. Therefore, it is still another purpose of this invention to provide for a simple serially fed parallel microprocessor interface to achieve the required processing speed.
At present, the microprocessors require numerous external chips which lower the system reliability and increase the system cost. Therefore, it is yet another purpose of this invention to lower the system cost and to increase its reliability by including on the microprocessor chip most of its associated hardware.
The present microprocessors require numerous external devices, which cannot take the full advantage of the future high density LSI technologies. And still another purpose of this invention therefore is to provide for future technologies by providing a self-contained logic microprocessor, having exclusively the I/O select and the data input and output pins.